The present invention relates to a mechanism in a rotary printing machine for adjusting the position at which an image is printed. More particularly, the invention relates to an image position adjusting mechanism having a printing cylinder, a rubber cylinder, and pressure cylinders, in which adjusting mechanism the printing cylinder slides along its axis to transversely adjust the printing position of the image and a gear of the printing cylinder slides along its axis to vertically adjust the printing position, e.g., with respect to a substrate upon which the image is to be printed.
Apparatus of this type are well known. One such apparatus is disclosed in Japanese Unexamined Patent Publication No. 56504/78. According to the image position adjusting apparatus shown in the Japanese Publication, a printing cylinder and a printing cylinder axis are integrally assembled and a drive gear is mounted outside a frame of the printing apparatus. An image transverse position adjusting knob is positioned inside a housing on one side of the apparatus, and an image vertical position adjusting knob is inside the housing at the other side. The printing cylinder shaft is rotatable and slidable relative to bearings provided on the frame or housing of the printing machine.
Vertical adjustments of the image in the conventional machine cannot be carried out by an operator standing at the one side of the printing machine, so coarse vertical adjustments cannot easily be repeated, especially when transverse adjustments are performed between vertical adjustments. In addition, access to the adjusting knobs is hindered because they are provided inside the machine frame, and construction of the machine is expensive due to a complicated bearing structure.